Field of the Invention
The present inventions relate to an imaging apparatus, a control method therefor and one or more storage mediums, and more particularly relates to the imaging apparatus, the control method and one or more storage mediums that can control exposure of the imaging apparatus under a light source which flickers.
Description of the Related Art
Sensitivity of an imaging apparatus such as a digital camera, a mobile phone, and a tablet-type device has been improved recently. This has allowed the imaging apparatus to obtain a bright image with less blur even in a darker environment such as indoors by capturing an image with a high shutter speed (i.e., shorter exposure time).
Fluorescent lamps and light emitting diodes (LEDs), which have proliferated as indoor light sources, produce flickers. This is a phenomenon where illuminating light blinks periodically according to the frequency of a commercial power supply. When images are captured with a high shutter speed under the light source which flickers (hereinafter referred to as a flickering light source), unevenness of exposure and non-uniformity of color may occur in one captured image, and variation in exposure and color temperature may occur among a plurality of images that are captured consecutively.
In order to address such problems, Japanese Patent Application Laid-open No. 2006-222935 has discussed a technique to detect a flicker state of illumination light and to adjust timing of image capturing so that the center of an exposure period is substantially aligned with the timing at which the light intensity of the illumination light becomes maximum.
When a timing of capturing an image is adjusted so as to match a timing at which the light intensity of the illumination light becomes maximum as discussed in Japanese Patent Application Laid-open No. 2006-222935, a release time lag occurs depending on a timing to issue an instruction to capture an image. This results in decreasing frame speed during consecutive image capturing.